diff --git a/builtin.c b/builtin.c
index 34865ec9a4bb..acd5635e2cae 100644
--- a/builtin.c
+++ b/builtin.c
@@ -490,9 +490,12 @@ static OP *ck_builtin_func1(pTHX_ OP *entersubop, GV *namegv, SV *ckobj)
     }
 }
 
-XS(XS_builtin_indexed)
+/* This does not use the XS() macro so that op.c can see its prototype */
+void
+Perl_XS_builtin_indexed(pTHX_ CV *cv)
 {
     dXSARGS;
+    PERL_ARGS_ASSERT_XS_BUILTIN_INDEXED;
 
     switch(GIMME_V) {
         case G_VOID:
@@ -638,7 +641,7 @@ static const struct BuiltinFuncDescriptor builtins[] = {
     { "load_module", NO_BUNDLE, &XS_builtin_load_module, &ck_builtin_func1, 0, true },
 
     /* list functions */
-    { "indexed",          SHORTVER(5,39), &XS_builtin_indexed,          &ck_builtin_funcN, 0, false },
+    { "indexed",          SHORTVER(5,39), &Perl_XS_builtin_indexed,     &ck_builtin_funcN, 0, false },
     { "export_lexically",      NO_BUNDLE, &XS_builtin_export_lexically, NULL,              0, true },
 
     { NULL, 0, NULL, NULL, 0, false }
diff --git a/embed.fnc b/embed.fnc
index f0d1dedb1485..b07525d90220 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -4088,6 +4088,8 @@ p	|void	|finish_export_lexical
 p	|void	|import_builtin_bundle					\
 				|U16 ver
 p	|void	|prepare_export_lexical
+p	|void	|XS_builtin_indexed					\
+				|NN CV *cv
 #endif
 #if defined(PERL_IN_CLASS_C) || defined(PERL_IN_OP_C)    || \
     defined(PERL_IN_PAD_C)   || defined(PERL_IN_PERLY_C) || \
diff --git a/embed.h b/embed.h
index 8f890fba4df4..f3a9c9ca17e0 100644
--- a/embed.h
+++ b/embed.h
@@ -1202,6 +1202,7 @@
 #     define get_aux_mg(a)                      S_get_aux_mg(aTHX_ a)
 #   endif
 #   if defined(PERL_IN_BUILTIN_C) || defined(PERL_IN_OP_C)
+#     define XS_builtin_indexed(a)              Perl_XS_builtin_indexed(aTHX_ a)
 #     define finish_export_lexical()            Perl_finish_export_lexical(aTHX)
 #     define import_builtin_bundle(a)           Perl_import_builtin_bundle(aTHX_ a)
 #     define prepare_export_lexical()           Perl_prepare_export_lexical(aTHX)
diff --git a/op.c b/op.c
index bc8df993cfaa..9dc1c79dc1cc 100644
--- a/op.c
+++ b/op.c
@@ -171,9 +171,6 @@ recursive, but it's recursive on basic blocks, not on tree nodes.
 
 static const char array_passed_to_stat[] = "Array passed to stat will be coerced to a scalar";
 
-/* UGH!! */
-EXTERN_C void XS_builtin_indexed(pTHX_ CV *);
-
 /* remove any leading "empty" ops from the op_next chain whose first
  * node's address is stored in op_p. Store the updated address of the
  * first node in op_p.
@@ -9825,7 +9822,7 @@ Perl_newFOROP(pTHX_ I32 flags, OP *sv, OP *expr, OP *block, OP *cont)
         if(firstarg == lastarg)
             firstarg = NULL;
 
-        if (op_is_cv_xsub(lastarg, &XS_builtin_indexed) &&                   /* a call to builtin::indexed */
+        if (op_is_cv_xsub(lastarg, &Perl_XS_builtin_indexed) &&              /* a call to builtin::indexed */
             firstarg && OpSIBLING(firstarg) == lastarg &&                    /* with one arg */
             (firstarg->op_type == OP_RV2AV || firstarg->op_type == OP_PADAV) /* ... which is an array */
         ) {
diff --git a/proto.h b/proto.h
index 65fe5c5bd68c..c64cad758b11 100644
--- a/proto.h
+++ b/proto.h
@@ -6202,6 +6202,12 @@ S_get_aux_mg(pTHX_ AV *av);
 
 #endif
 #if defined(PERL_IN_BUILTIN_C) || defined(PERL_IN_OP_C)
+PERL_CALLCONV void
+Perl_XS_builtin_indexed(pTHX_ CV *cv)
+        __attribute__visibility__("hidden");
+# define PERL_ARGS_ASSERT_XS_BUILTIN_INDEXED    \
+        assert(cv); assert(SvTYPE(cv) == SVt_PVCV || SvTYPE(cv) == SVt_PVFM)
+
 PERL_CALLCONV void
 Perl_finish_export_lexical(pTHX)
         __attribute__visibility__("hidden");